/Engine/Plugins/Runtime/NetworkPrediction/Source/NetworkPrediction/Public/NetworkPredictionSerialization.h
How many bits we use to NetSerialize Frame numbers. This is only relevant AP Client <> Server communication. Frames are stored locally as 32 bit integers, but we use a smaller number of bits to NetSerialize. The system internally guards from Frame numbers diverging. E.g, the client will not generate new frames if the last serialization frame would be pushed out of the buffer. Server does not generate frames without input from client.
enum { NUM_BITS_FRAME = 8 }